Whirling psychrometer for measuring humidity
1950-1953
Aspirated psychrometer by Casella
1930
Clockwork aspirated psychrometer, Mk3
1971
Assmann psychrometer by Casella
1944
Clockwork aspirated psychrometer by Casella
1950-1970
Assmann psychrometer
1922
Wet bulb in aircraft psychrometer housing, 1940s.
1940-1950
Aspirated electric psychrometer
1997
Strut psychrometer Mk VA wet and dry bulb alcohol in glass Fahrenheit thermometers
Psychrometer scale, of paper on wooden frame.
Psychrometer by Casella
Casing for clockwork psychrometer
1940-1950
Clockwork aspirated psychrometer
Assmann psychrometer by Friedrichs & Co
1950-1960
Clockwork psychrometer
1935-1945
M.O. Balloon psychrometer
1945
Whirler for psychrometer, c. 1918.
1918
August psychromete
1876
Assmann psychrometer by C. F. Casella
1919
Air Psychrometer Mark V, with aircraft wing strut mounting straps
Whirling psychrometer
1920-1940
Direct reading psychrometer
1924
Comins electro-psychrometer by the American Moistening Co.
1910
Clockwork psychrometer by R. Fuess
1938
Clockwork and fan for psychrometer by Salmoiraghi
1940-1950
Whirling psychrometer
1950-1960
Strut psychrometer
1930
Strut psychrometer Mark VB
1943
Regnault type hygrometer with mercury thermometer
1866
Wet and dry bulb hygrometer, British, 1986
1986
Aircraft strut psychrometer
1927
Aeroplane psychrometer Mark II, 1918-1922.
1918-1922